Asbestos-cement pipe



' Jan. 13, 1942. A. B. c:|-|R|s1'o|= l-|ERy V AsBEsTos-CEMEYNT PIPE 'Filed Aupa,l 1940 2 ,sheets-sheet 1 v BY. n

l 'l ATTORNEY,

' n' of' the pipe.

` Patented Jan. 13, 1942 l UNITED) l ratione! New Jersey y )applicata Amma, i949; sentis 350,37; ys claims. `(ci. l13a-430i f This invention relates to an.,asbestos-crerrlveni,Vv

Y 4pipe, and more particularly to a pressure pipe y vfor use in conducting water .or other liquid under high pressure. f .y i. The principal object ofthe inventionvisto pro.-

videan extruded asbestos-cementpipe of'gxjeaty structural rstrength and' maximum' densitylnhav ing smoothand straight'exterior and interior surfaces of uniform-.diameter throughoutgwhich pipe is formed of a homogeneous plastic cement composition reenforced throughout lts lengthand thickness with fibers that extend substanf tially in the directionk In the-practicerofmy invention, 'Igemploy a composition ofy plastic consistency comprising a.

mixture of 'hydraulic cement,` suchas Portland cement, asbestos fibers, and water,` with or Without llers'or inert material. A mass of the plastic material lis fedf under substantially constant pressure and at a sub-2 Astantially uniform rate of flow through'asta'- tionarydie by 'whichitis shaped into tubular,`

formp During itspassage throughthe 'die the `v mass is compressed or -compacted to a-high-de-l mum density.

gree to integrateand unite the cement particles f and the bers into a homogeneous'body omaximixture composed principallyofuPortlandcement `containing from about 10% `to 20% 'byweight- An important feature of the invention consists' inproviding' an asbestos-,cement pipe in which the fibers extend in ka direction substantially e ,smopt'hf` inside vand out, and I jtl ierefcreidce .n v'{z,z69,43s 'fifi Y f Y Arthu'rfn. cnristopiier, Audubon, r1.1., assignbr to The Ruberoid Co., NewYork, DLX.; a corpo-jv graces," both any subsequent m"`chiningfor 'fin1sh"ng"oper`a' a very,low?cogemclent"oirfresistanc'e"-tothe flow of liquid. The smooth' outer surface' and c ontrolled wall thicknessv facillilat'esthey uniorihfthe n'sectixfis v n y couplings/without the necessity., of., machining or n ofthe pipe with -the use of conventional lathin's. :f

fluences, land to corrosin or V"eros Fig.` 3` is ay vertical cross ect'io hopper, taken on the .,lnev 3-,- 'f

and i w oi. aiflagf Fig. sjisaiongitudmx section .of unopened; rspicules orbundles of relatively u parallel to the longitudinal axis 1of the-extrudedv ing to this inventionrnay be formed iny conz tinuous sections of any' desired lengths'having uniformly straight bores and outer surfaces.- y l u Y the' machine Ifrom. whichfnit is fed, tol the auger Water' is addedv to;.the-mixtu'regin` suicient .guanktity to formfamoist', as distinguished ,from a wet,

' A'r'nassfof plastic consistency."-

Because of the fact that the iiber reenforcement 1* extends lengthwise of the pipes, they are found to be much stronger in respect to bursting strength than similar pipes of equal wall thick- Thematerialiis placedl intoA of or screw il mounted'to rotate in the barrel or` casing` I2 which is preferably provided with a detachable liner I3. The hopper is equipped withs a feeding` device, as best seen in Fig. 3, that operf .ates totampthe material into the channel 2l l side of the hopper and `xed to a rock-shaft I5 'that iS rocked by an eccentric I6 through an' arm i1 and crank I8. f n

' I'he rear end 20 of the auger is rkeyed at 22 ytoa, rotary shaft v23.y The shaft 23 issupported at two ormore spaced points on suitable thrustbearings 24, of which only one set isshow'n, and is driven-through a. coupling 26 by means ofen -electric motorand reduction gear (not shown) .3*

,niet require housed in the casing 2li, although A.other suit- "able driving means may be The front end i9 of the augeris supported on a cylindrical bearing 21 secured to a spider 28.v The spider has a plurality of arms 29generally four, which are prefcrablyarched to .assist in resisting the thrust caused by extrusion of the material, and which are placed at substantally the angle atA which the material comes off the auger and. are-of such design as to cause the thinnest possiblecut in the material consistent-with the required strength of the spider construction. y Y

The auger tends to extrude the material in a swirl or worm with a spiralorientation of the fibers- This has been foundto be objectionable.r l

To overcome this disadvantage, I vequip the machine .withplacerfblades 30, vgenerally three or lfourmounted on a sleeve or collar 3| xed to the front end I9 of the auger'to rotate with the auger. The blades are pitched at a suitable angle y tothe axis of Irotation of the auger,or they may `be constructed as to permit of adjustment .of

the pitch, to direct the'bers longitudinally and 1 to distribute the material uniformlyV in thek en- "larged entrance chamber 32 of the expressingdie' 33. Thevblades are so timed and spaced that they miss the nights-'of' the auger, and theymay be disposed either'in back" 'orin front of the.

and replacing the auger. Dies and cores of different sizes may be used interchangeably on the machine to form pipes of different diameters and wall thicknesses.

The compacted asbestos-cement material by being forced through the space between the stationary die and core members is extruded in a uniformly straight tube of predetermined diameter and thickness, having smooth exterior and interior surfaces, and free from kinks, dents or bulges.

The,extruded pipe 38, shown in Fig. 5, comprises a tubular body lof cement reenforced throughout with asbestos fibers 39 that run lengthwise, substantially parallel to the longitudinal axis of the pipe, and that are rmly embedded and bonded in the cement.

Asgextruded, the pipe is sufciently self-sustaining that it may be cut into lengths and handled without deformation. The cut lengths may be set in any usual manner, which setting may be accelerated by use of an autoclave.

The extrusion process and apparatus shown and described herein are claimed in a companion application, Serial Number 350,373 o August 3,

The present application relates to the extruded pipe, and it is to be understood that in making the pipe other suitable j extrusion apparatus may be used.

Fig. 4. has convex'lwalls curving from the dis.

charge end of the auger to .the tube forming portion `of the die, and is shaped tocompress,` f A,the material in its passage into the die.

The opening into the chamber is considerably larger than its exit, generally about three to four times .as,l`large. Due tothe combined .action of the feed of theauger and the constricted shape of -the chamber, `a mass-of materialfwiil be gathered in the chamber and densely compacted vso asto t be free of voids by the pressure built up therein.

In passing between the arms 29 of the spider the material is'divided into sections. However, these sections are united and knit together when the material is subjected to compression in the chamber.

. The die 33.is attached by bolts 34 or otherfastening means to the front end of the vcasing I2. Concentrically disposed within the die is a. stationary core 35. The core issupported so that it cannot lwabbleon a rod 3,6 xed to-the spider 28. A nut 31 on the threaded end of therod permits of detachingthe core. U-pon detaching the die the spider 28 may be slid out of the front end of the casing to permit of Ademounting 1. As a new article of manufacture, an extruded asbestos-cement pipe composed of a hardened plastic mixture of cement and asbestos ber in which substantially all the fibers are mechanically arranged during extrusion to run lengthwise of the pipe. v

2. As a new article `of manufacture, an extruded asbestos-cement pipe composed of a hardened plastic cement mixture containing not more than about 29% by weight of asbestos bers distributed substantially uniformly throughout and in which the fibers are mechanically directed during extrusion to extend substantially lengthwise of the pipe.

3. An asbestos-cement pressure pipe of high bursting strength formed of an extruded, compacted mixture of cement reenforced with from about 10% to 20% by weight of short asbestos fibers, in which the bers are mechanically directed during extrusion to extend substantially lengthwise of the pipe and are uniformly distributed throughout, said pipe having a straight and smooth tubular wall,'of uniform thickness, and 0f constant inner and outer diameters,

throughout its entire length.

ARTHUR B. CHRISTOPHER. 

